1. Field of the Invention
This invention relates to compositions for protecting semiconductor elements, hereinafter referred to as protectant compositions, and to semiconductor devices coated with these compositions.
More particularly, this invention relates to protectant compositions that provide highly moisture-resistant and highly heat-resistant semiconductor devices and to semiconductor devices coated with these compositions.
2. Background Information
To protect the semiconductor element(s) in semiconductor devices from such insults as external stresses, alpha-radiation, and the like, the surface of the semiconductor element is typically coated with cured silicone compositions, as described in Laid Open Japanese Patent Application [Kokai or Unexamined] Number Sho 63-35654 [35,654/1988] and Laid Open Japanese Patent Application [Kokai or Unexamined] Number Hei 3-166262 [166,262/1991]). This assembly is then sealed with a molding compound such as an epoxy resin.
Several problems are associated with this type of semiconductor device due to the difference in coefficients of thermal expansion (CTE) between the epoxy resin sealant and the cured silicone material. When the fabricated semiconductor device is tested for its moisture and heat resistance, this CTE mismatch causes such defects as the development of voids or gaps at the interface between the resin sealant and cured silicone and deformation or breakage of the bonding wires--which electrically connect the semiconductor element and lead frame--by internal stresses generated between the resin sealant and the cured silicone.
One objective of the present invention is to provide compositions for protecting semiconductor elements which afford highly moisture-resistant and highly heat-resistant semiconductor devices. An additional objective of the present invention is to provide highly moisture- and heat-resistant semiconductor devices.